A variety of medical conditions may cause a patient to use an orthosis, which is a device that is externally applied to a patient's body to aid or supplement the patient's neuromuscular and skeletal system. Patients with hypotonia, for example, may have low muscle tone in certain leg muscles and may require the aid of an orthosis to provide support to lesser toned muscles. The orthosis helps the patient walk without collapsing forward or hyperextending backwards due to the inability of the lesser toned muscles to support the patient's body. As another example, patients with hypertonia may have high muscle tone in certain leg muscles (e.g., calf muscle) and may require the aid in an orthosis to position the foot in a relaxed or more natural position, and to help the make sure the foot does not hang and drag as the patient walks. With these types of conditions, among others, an ankle-foot orthosis (hereinafter “AFO”) may be beneficial to help correct the imbalance of muscles in the patient's legs.
An AFO is a type of orthosis that supports both the foot and the ankle by controlling the position and motion of the ankle. As mentioned above, an AFO can be used by for both weak, lesser toned limbs and contracted limbs. In addition, an AFO can be used for immobilization purposes (e.g., broken bone). Conventional AFO's form an “L” shape with an upper support that contacts a posterior side of a patient's lower leg with a strap securing around the patient's calf and a lower support that contacts an inferior side of the patient's foot. In conventional AFO's, there may or may not be a hinge mechanism at the ankle and there may or may not be additional straps throughout the “L” shape to secure the brace to the patient's leg.
Certain AFO designs may also include a Supra-Malleolar orthosis (hereinafter “SMO”) that fits within the AFO to provide additional forefoot, mid-foot, and subtalar stability. Conventional SMO's wrap around a patient's foot and ankle to compress the soft tissue of the foot. The compression of the SMO helps to stabilize the foot and ankle, which helps the patient develop a more natural gait when walking.
While beneficial and useful to patients, some conventional AFO designs still suffer from many drawbacks.